As shown in Japanese patent unexamined publication 2005-98003 (patent document 1), a conventional flush toilet for discharging waste by flushing the toilet with flush water is known. In the conventional toilet, the inner circumference of a rim portion formed at the top edge of the bowl portion of the flush toilet is formed to have a vertical or outward-spreading shape, whereby flush water is spouted in a horizontal direction from a water spouting port formed on the rear side of this rim portion so as to form a swirl flow, and is spouted toward a discharge trap from a jet spouting port erected at the bottom and front end of the bowl portion to generate a siphon effect, thereby discharging waste.